Motor vehicles are generally provided with an internal combustion engine. A suction system supplies the internal combustion engine with combustion air. Charge air cooling is often provided to reduce the temperature of the drawn-in air and to increase the density of the air. The charge air cooling contributes to better filling of the cylinders. This affords advantages particularly when a charging of the internal combustion engine is provided and the charge air is heated as a result of compression or the internal combustion engine has an exhaust gas return in which the hot exhaust gas is introduced into the suction system upstream of the cooler. In both cases, cooling air prior to introduction into the cylinders has been found to be particularly advantageous.
The arrangement of the internal combustion engine and the associated units or components with respect to each other in the engine compartment is subjected to many requirements. Arranging the suction system in the engine compartment relative to the bodywork of a motor vehicle creates problems relating to meeting all of the requirements.
The structure of the assembly carrier and the bodywork-related arrangement of the engine, in particular the suction system, in the motor vehicle is arranged to improve the favorable crash behavior of the vehicle. Absorption of accident energy and deformation of the bodywork to maintain passenger compartment survival space is a priority. Providing sufficiently large deformation paths leads to a corresponding spacing of the engine from the walls of the engine compartment, for example, the engine hood, the cover plates and the assembly carrier.
FIG. 1A is a perspective illustration of a fragment of an assembly carrier 11 according to the prior art together with the suction system 12. The assembly carrier 11 is part of a bodywork of a motor vehicle in the front end region and has four web-like carriers 11a, 11b, 11c, of which in FIG. 1A only three carriers 11a, 11b, 11c are illustrated or indicated. In the shown installation position of the assembly carrier 11, an upper carrier 11c which extends transversely has two lateral carriers 11a, 11b which are spaced apart from each other. The four carriers 11a, 11b, 11c of the assembly carrier 11 form a frame which generally serves to receive a cooling device.
The suction system 12 is partially arranged above the assembly carrier 11 and at the rear side or the inner side of the assembly carrier 11. The suction system 12 serves to supply the internal combustion engine with air and has to this end an air inlet opening 12a. The air striking the front end region of the motor vehicle is directed from the outer side of the assembly carrier 11 via an indentation or recess 13 (shown in FIG. 16) to the rear side of the assembly carrier 11 and into the air inlet opening 12a of the suction system 12. Air is often supplied to a filter to be cleaned by the suction system 12.
FIG. 1B shows in an enlargement the connection of the suction system 12 to the assembly carrier 11 according to FIG. 1A, wherein the suction system 12 is illustrated offset to the rear in order to make the indentation or recess 13 clearly visible.
The indentation or recess supplies air to the suction system but weakens the upper carrier of the assembly carrier and reduces the rigidity of the upper carrier. There is generally more than one indentation provided in the carrier to accommodate a large number of variants using one assembly carrier. This design of the upper carrier enables the installation of suction systems with one air inlet opening or installation of suction systems with more than one air inlet opening. Suction systems with two or more air inlet openings and of different lengths that require different indentations. The rigidity of the assembly carrier is reduced as the number of indentations increase.
The web height of the upper carrier cannot be freely determined or selected with regard to the rigidity of the upper carrier. The web height is significantly influenced or limited by the legally prescribed pedestrian protection and the spatial requirement of increasingly larger cooling devices received by the assembly carrier. The suction system is arranged partially above and partially behind the assembly carrier and must be taken into account. The confined spatial conditions, significantly limits the structural configuration of the assembly carrier or the upper carrier, and positioning of the suction system.
Pulsations of the internal combustion engine may cause the suction system to oscillate.
The increasing noise emission is an environmental problem that has a disadvantageous effect on the quality of life and the health of persons subjected to the increasing noise. A large number of regulations have been introduced to limit noise. The regulations include the Bundes-Immissionsschutzgesetz (BImSchG) (Federal Emission Protection Act) and the guidelines of the European Commission.
The internal combustion engine is the dominant source of noise of the motor vehicle, but all sources of noise that contribute to the overall noise emission must be taken into consideration to comply with the increasingly strict regulations with regard to the admissible noise emission of a motor vehicle.
Attempts are made to influence and model the noise caused by the internal combustion engine in a selective manner by noise design or sound design. Customers purchasing a vehicle are influenced in a significant manner and to an increasing extent by the noise of the internal combustion engine of the vehicle.
High frequency noise may be caused by oscillation excitation of the suction system. Prior art means for reducing noise emissions may include resonators for damping noise.
Installing a resonator in the suction system requires greater cross-sections or large-volume suction systems. Providing a resonator increases the rigidity of the suction system.
Against this background, an object of the present invention is to provide a motor vehicle with an improved assembly carrier in particular with regard to rigidity by providing the air supply to the suction system with cost advantages.